Acne Articles

Doctors are being warned to limit the use of antibiotics for the treatment of acne, amidst growing rates of antibiotic resistance in patients with the disorder.

For more than 40 years, antibiotic therapy directed against the acne-causing bacterium, Propionibacterium acnes, has been the mainstay of treatment for moderate (rather than mild or severe) acne. Commonly used antibiotics for acne include erythromycin, clindamycin and a group of antibiotics called tetracyclines.

This week, Dermatologists and Microbiologists from Harrogate will present findings at the British Association of Dermatologists’ Annual Conference in Manchester that may challenge this practice, while a study from King’s College Hospital in London will show growing rates of antibiotic resistance among all dermatology patients.

The Harrogate researchers measured the numbers of Propionibacterium acnes colonising the skin of 994 patients referred to the hospital Dermatology department between 2004 and 2013 and assessed what proportion of them were resistant to common antibiotics used to treat acne.

The study, supported by a grant from the British Skin Foundation, revealed that up to 79.5 per cent of patients were colonised by bacteria resistant to erythromycin or clindamycin or both.

The proportion of patients colonised by tetracycline-resistant bacteria was lower (14.2 to 25 per cent), but did rise to 68.2 per cent one year (2011) for reasons that are currently unclear. Most patients were colonised by a mix of both resistant and non-resistant bacteria.

There is evidence to suggest that patients carrying antibiotic resistant Propionibacterium acnes may respond less well to antibiotic therapy used to manage their acne. It has also been shown that these resistant bacteria can be spread by direct contact from one person to the next.  

A second study due to be released at the conference looked at the resistance to antibiotics of another bacterium, called Staphylococcus aureus, which is a common cause of skin infections. The researchers, from King’s College Hospital in London, found that 30 per cent of samples taken from general dermatology patients (rather than acne patients specifically) in 2014 were resistant to the antibiotic erythromycin compared to 17 per cent in 2007.  24 per cent of samples in 2014 were resistant to clindamycin, but it is not known if this is an increase from previous years.

Nina Goad of the British Association of Dermatologists said: “The growing resistance to antibiotics among skin patients generally and among acne patients more specifically, as highlighted by these two studies, is of concern. Antibiotics are important for treating skin infections, which are common in many skin diseases like eczema. Acne affects a huge number of people – 80 per cent of teenagers experience acne and while for most people it will disappear with age, for some it continues well into adulthood. If left untreated it can have a big psychosocial impact and cause scarring, so clearly this is a problem that needs to be managed.”

Consultant Dermatologist Dr Alison Layton from Harrogate, one of the acne study’s authors, explained: “Against a background of global concern about rising antibiotic resistance rates in major bacterial pathogens, GPs

may be unaware that resistance rates in skin propionibacteria are so high. These results highlight the need to use antibiotics judiciously when managing acne and to ensure that alternative effective agents are used, such that reliance on antibiotics is reduced whenever possible.”

Acne occurs when the sebaceous (oil-producing) glands are particularly sensitive to normal blood levels of certain hormones, causing the glands to produce an excess of oil. The build-up of oil creates an ideal environment in which Propionibacterium acnes can multiply. At the same time, the dead skin cells lining the pores are not shed properly and clog up the follicles, producing blackheads and whiteheads.